Skip to main content
ARS Home » Pacific West Area » Riverside, California » National Clonal Germplasm Repository for Citrus » Research » Publications at this Location » Publication #417837
Research Project: Citrus and Date Genetic Resource Conservation and Utilization

Location: National Clonal Germplasm Repository for Citrus

Title: History of citrus classification from Imperial China to the present day

Author
item OLLITRAULT, PATRICK - Inrae
item CURK, FRANCK - Inrae
item Krueger, Robert

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/19/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: From imperial China (23rd century BC) to the 21st century we inherited a natural history of citrus rich in classifications with a large number of varieties, mutants and hybrids described as real species. The extraordinary ability of citrus fruits for interspecific hybridization and the fixation of the phenotypes of hybrids and spontaneous mutants by apomixis did not facilitate the task of the taxonomists. Even today several taxonomic systems still used. Two of these classifications mainly based on morphological traits were proposed in the sixties by Tanaka and Swingle and Reece. More recently, a new classification, taking into account the first results of molecular biology and biological evidences, was proposed by Mabberley in 2004. It widely modified the status of the Citrus genus, including all the sexually compatible species of the former genera Clymenia, Eremocitrus, Fortunella, Microcitrus and Poncirus. It also highlighted the interspecific admixture status of a certain number of species using the hybrid “x” symbol between the genus and species names. This new vision of the botanical world of citrus fruits was an important step forward, but lacked the genetic information that has since been published. Moreover, the Mabberley system results to consider in the same species different horticultural groups with strong phenotypical differentiation, such as sweet oranges, grapefruits and clementine, all included in C. x aurantium. Tacking advantage of more recent genomic and genetic data Ollitrault, Curk and Krueger proposed, in 2020, a trinomial system where ancestral admixtures define the species level and individual reticulation events the variety level. After an historical tour of the different way to classify plants in general and specifically citrus, we explain this new trinomial Citrus classification for managing genus, species, variety and hybrid levels under an unambiguous system based on phylogenomy.